Process and apparatus for the control of spinning machines

ABSTRACT

Apparatus for controlling a spinning machine having a plurality of spindles in a plurality of individual spinning stations is provided either with sensors allocated to the spindles for surveying thread breakages or with a sensor that cyclically traverses the spinning stations. The sensor or sensors signal the number of breakages during a predetermined time unit to a counter. The resulting value, together with a limit value delivered by a preselection device is fed to a comparison device. Depending on whether the comparison device registers an amount above or below the limit value by a determined number of thread breakages, a signal is delivered to an adjusting device which proportionally reduces or increases the speed of the spindles. Where a single sensor is used, this together with an automatic thread knotting device, may traverse the spinning stations. The counter and a cooling matrix travel with the sensor and are arranged to transmit signals to a stationary interrogator which feeds the information to the comparison device. In a modification, the cyclically moving unit transmits a signal to a stationary switching device controlling a time transducer each time the knotting device completes a cycle, the outputs of the switching device and time transducer being fed to the comparison device.

United States Patent [1 1 Vignon [451 Sept. 30, 1975 PROCESS AND APPARATUS FOR THE CONTROL OF SPINNING MACHINES [75] Inventor: Louis Vignon, Geneva, Switzerland [73] Assignee: Heberlein I-Iispano SA,

Vernier-Geneva, Switzerland [22] Filed: Feb. 20, 1974 [21] App]. No.: 444,162

[30] Foreign Application Priority Data Feb. 20, 1973 Switzerland 2388/73 [52] US. Cl 57/34 R; 57/81; 57/93; 57/ 156 [51] Int. Cl. DOlI-I 13/16; DOlH 13/32 [58] Field of Search 57/34 R, 78, 80, 81, 22, 57/93, 156

[56] References Cited UNlTED STATES PATENTS 1,412,518 3/1922 Guildford 57/93 3,430,426 3/1969 Bryan et al. 57/81 X 3,486,319 12/1969 Lee et al. 57/34 R 3.521.441 7/1970 Lamparter... 57/93 X 3.521413 8/1970 Ford et al. 57/34 R 3.523.415 8/1970 Suzuki 57/81 3,831,005 8/1974 Schippcrs et a1. 57/93 X Primary liruminer-Donald E. Watkins Attorney, Agent, or Firm--Larson, Taylor & Hinds 5 7 ABSTRACT Apparatus for controlling a spinning machine having a plurality of spindles in a plurality of individual spinning stations is provided either with sensors allocated to the spindles for surveying thread breakages or with a sensor that cyclically traverses the spinning stations. The sensor or sensors signal the number of breakages during a predetermined time unit to a counter. The resulting value, together with a limit value delivered by a preselection device is fed to a comparison device. Depending on whether the comparison device registers an amount above or below the limit value by a determined number of thread breakages, a signal is delivered to an adjusting device which proportionally reduces or increases the speed of the spindles. Where a single sensor is used, this together with an automatic thread knotting device, may traverse the spinning stations. The counter and a cooling matrix travel with the sensor and are arranged to transmit signals to a stationary interrogator which feeds the information to the comparison device. ln a modification, the cyclically moving unit transmits a signal to a stationary switching device controlling a time transducer each time the knotting device completes a cycle, the outputs of the switching device and time transducer being fed to the comparison device.

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US. Patent Sept. 30,1975 Sheet4 01-4 3,908,347

Fig 3 PROCESS AND APPARATUS FOR THE CONTROL OF SPINNING MACHINES FIELD OF THE INVENTION This invention relates to a method of and an apparatus for controlling spinning machines having a number of spinning stations, the spindles of which are rotated by a spindle driving device, and at least one automatic thread-knotting device movable along the spinning stations.

DESCRIPTION OF THE PRIOR ART ln spinning machines, automatic thread knotting devices are used more and more frequently which cyclically survey the individual spinning stations and, upon registration of a thread breakage, induce knotting of the threads and restart the spinning operation. The spindle speed is regulated in accordance with the material being processed so that the number of thread breakages that may arise does not exceed the capacity of the automatic thread knotting device. For determining the admissible spindle speed depending on the number of thread breakages, there are experimental values which, however, are so low that even under extraordinary circumstances such as, in particular, material defects, the number of thread breakages per time unit is still below the maximum value admissible for disturbance-free operation.

OBJECT OF THE INVENTION As can be seen, by a combination of the above described devices, the output of a spinning machine can be brought to an optimum value with a minimum of difficulties.

SUMMARY OF THE INVENTION Accordingly, there is provided a method by which it is possible to avoid or at least reduce the disadvantages of the known devices and in particular to control the spindle speed of spinning machines, on the one hand in order to increase the capacity of the machines and on the other to improve safety in operation.

According to the present invention, this problem is primarily resolved by continuously surveying the number of thread breakages in the individual spinning stations and comparing it with a predeterminable limit value, and depending on whether the said value exceeds or falls short of the limit value, the speed of the spindle drive device is reduced or increased.

In practice, the invention can be realized in a particularly simple manner if there is provided at least one sensor for determining the number of thread breakages in the individual spinning stations as well as a counting 'and/or comparing device fed by the sensor for comparing the number of thread breakages with at least one predetermined limit value and if at least one signal device controlled by the comparing device is provided for controlling a spindle driving device for reducing the spindle speed upon increase of the number of thread breakages and for increasing the spindle speed upon decrease of the number of thread breakages.

It is particularly easy to determine and evaluate the number of thread breakages if, when using an automatic thread knotting device for indirectly ascertaining the number of thread breakages, there is provided at least one surveying station for comparing the time actually needed by the thread knotting device for one cycle with a predetermined amount of time.

Particularly exact determination of the number of thread breakages and therefore particularly exact control of the spindle speed to the maximum admissible speed can be achieved if the thread sensor is connected with a counting device for adding the number of determined thread breakages during a predetermined amount of time for delivery of control signals, for reducing or increasing the spindle speed, to an adjusting device that determines the spindle speed.

In this case, if high precision is required, an individual thread sensor can be provided for each spindle. With respect to economies, it may however also be advantageous in certain practical cases to provide for a plurality of spinning stations a common thread sensor movable cyclically along the stations.

In this case, the thread sensor may be continuously connected with the counting and/or comparing device or else be provided with a storage device in order to reduce the number of transmission conductors, the storage device registering the thread breakages and transmitting in certain time intervals their number to stationary interrogators which deliver the positioning signals to the adjusting device.

For storing such signals, iron cores are particularly suitable which can be magnetized or the magnetic polarity of which can be reversed since these iron cores may be interrogated by electromagnetic sensors as well as used for actuating relay contacts, especially reed relays.

Control can then be effected particularly rapidly and precisely by means of an adjusting device which contains, as active element, a stepping motor. By the signals delivered by the comparison device, depending on the type of regulator, the spindle speed can be influenced by means of an on-load switch or by a potentiometer.

There has thus been outlined rather broadly the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject of the claims appended hereto. Those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be used as a basis for the designing of other structures for carrying out the several purposes of the invention. It is important, therefore, that the claims be regarded as including such equivalent constructions as do not depart from the spirit and scope of the invention.

DESCRIPTION OF THE DRAWINGS In order that the invention may be clearly understood and readily carried into effect, methods and apparatus in accordance therewith will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1a shows a schematic representation of a spinning machine with a number of spinning stations provided with a control device for the spindle speed;

FIG. lb shows a modification of the spinning machine of FIG. la;

FIG. 2 is a schematic representation of an electrical control circuit; and

FIG. 3 is a schematic representation of a modification of the control circuit of FIG. 2.

FIG. 1a shows schematically a spinning machine 1 with a plurality of spindles 2 arranged in a plurality of individual spinning stations. On each of the spindles 2, there is provided a sensor 3 for surveying thread breakages. By means of a transmission conductor 4, thread breakages are signalled to a counting device 5 which determines the number of thread breakages during a predetermined time unit; The resulting value is fed, to-

gether with a limit value delivered by a preselection device 6, to a comparison device 7. Depending on whether the comparison device registers an amount above or below the limit value by the determined number of thread breakages, a signal is delivered to an adjusting device 8 which proportionally reduces or increases the speed of a spindle driving device 10 via a control conductor 9.

The spindle driving device 10 for example drives all the spindles 2 by means of a schematically shown tangential belt 11 so that speed increase or reduction of the spindle driving device 10 also effects increase or reduction of the speed of all spindles 2. In this manner, considerable safety of the spinning machine in operation is assured. Thereby, an automatic thread knotting device 13 moving cyclically along the spinning stations on a rail 12 can in time repair all occurring thread breakages. The thread knotting device 13, upon registration of a thread breakage by a sensor 3, is stopped in front of the spinning station concerned and activated for starting the knotting procedure.

FIG. 1b shows another embodiment of the present invention which has only one sensor 3 with a knotting device 13. The transmission of information on thread breakages is the same as in FIG. lla.

As the construction of the spinning machines as well as the automatic thread knotting devices are generally known, the details of construction of these elements will not be discussed here in detail.

The signals transmitted by the sensor 3 are only used for controlling the comparison device 7. It is, however, advantageous in certain cases to use the sensors 3 at the same time for activating the thread knotting device.

The circuit elements shown in the block circuit diagram, such as counting device 5, preselection device 6', comparison device 7 and adjusting device 8 may be provided in a known way for analogue as well as digital counting of thread breakages and for effecting the comparison with the limit value. The sensors 3 may, of course, also not be associated respectively with individ' ual spinning stations, but alternatively with a plurality of spinning stations, as is for example the case in the following example:

FIG. 2 shows a modified example of a control device in which a sensor 3a moving cyclically along a plurality of spinning stations for surveying transmits, upon each passage past a stationary interrogator 14, the determined number of thread breakages. The sensor 3a in this case has a known electromagnetic measuring element 15 which, upon movement past the individual spinning stations, determines thread breakages by surveying the traveller rotation in each spinning station. A counter 16 is connected with the measuring element 15 which adds the thread breakage impulses delivered by the measuring element and transmits them to a coding matrix 17. The coding matrix itself is connected with several coils 18 which induce or reverse magnetic polarity in soft iron cores 19 to represent the actual amount in the counter in binary code. The soft iron cores 19 assure reliable storage of the actual counter result and at the same time make it possible in a simple manner to transmit the information to the interrogator 14 upon cyclic passage past the, same. For this purpose, on the latter, four reed contacts 20 are arranged on the level of the soft iron cores at the same distances between each other as between the iron cores. Depending on the level of the result stored by magnetization of the soft iron cores 19, one or several reed contacts 20 are closed and thereby corresponding information transmitted without mechanical connection with sensor 3a.

On the interrogator 14, furthermore, there is provided a coil 21 which is so excited after the measured value has been transmitted to the interrogator 14 that a contact 22 'on counter 16 is closed to reset the counter to zero, thereby preparing it for a new cycle. By the interrogator 14, the determined number of thread breakages as well as the limit value stored in the preselection device 6 is transmitted to comparing device 7 via amplifiers 23. As in the example of FIG. 1, a signal for reducing or increasing the speed of the spin-- dle driving device 10 is delivered, depending on whether it exceeds or is less than the limit value. This signal is constituted so that, depending on the required speed variation, a signal for left-hand or right-hand rotation is delivered to a step motor 24 provided in the adjusting device. The number of impulses which are delivered to the stepping motor 24, and therefore the amount of angular deviation, also depend on the amount of the required speed correction. The stepping motor 24 itself is connected mechanically with the slide of a potentiometer 25 which is in the supply circuit of the spindle driving device 10 so that the impulses delivered by the comparison device 7 at any time effect the desired reduction or increase of spindle speed.

Although the use of an electric step motor 24 in the adjusting device assures a particularly simple construction of the comparison device 7 and furthermore high precision, naturally also any other type of positioning unit, for example electromechanical or hydraulic, may be used. Also, the control of the spindle driving device 10 need not necessarily be effected by means of a potentiometer, but may also be effected by any other type of control device, such as for example an on-load switch or a thyristor control device.

By the comparison device 7, furthermore, two lamps 26 and 27 are controlled, one of which is lighted upon excessive spindle speed and the other one upon too low spindle speed. The lamps therefore at any time inform the operating staff if the control device is in operation and if there is a deviation from the predetermined limit value in one or the other direction, of the necessity of an alteration of the limit value. If such deviations from the limit value are frequently observed in one or the other direction, the necessity of an alteration of the 4 limit value stored in the preselection device 6 may be concluded therefrom.

It is also schematically indicated in FIG. 2 that the sensor 3a is fixed to the thread knotting device 13 with which it is electrically connected by means of a signal conductor 28. In this way, it is possible to limit the movement of sensor 3a along the spinning stations to a minimum since the knotting device (as shown in FIG. l) in any event moves simultaneously along the spinning stations.

The device shown in FIG. 3 is based on the indirect registration of the thread breakages by measuring the time necessary for one or several cycles of a thread knotting device 30.

For an arrangement of 250 spindles, for example, it has been determined that the thread knotting device needs 6 minutes for one cycle provided there are no thread breakages.

The number of thread breakages admissible for an optimal working rate of spinning machines is 60 thread breakages per 1000 spindles per hour, i.e., l5 thread breakages per hour for 250 spindles or 1.5 thread breakages per 6-minute cycle of the thread knotting device. The time necessary for knotting one thread is 1 minute so that, for a complete cycle with corresponding tolerance difference, there results a time consumption of 8 minutes.

The time is preselected on a time transducer 31 which, at the beginning of each cycle by the thread knotting device, is reset to zero by means of magnet 32,

reed relay 33, switching device 34 and control conductor 35. If, because of too high a number of thread breakages, the thread knotting device does not effect resetting of the time transducer to zero within 8 minutes, a signal is delivered to a comparison device 36 which is also connected to the switching device 34 by way of a switch 42. The comparison device 36 itself delivers control signals to a step motor 37 to adjust potentiometer 38 and to reduce the speed of the spindle driving motor 39. Furthermore, a lamp 40 is activated which indicates reduction of the spindle speed.

If, however, because of a lower number of thread breakages, the thread knotting device 30 activates the switching device 34 via magnet 32 and reed relay 33 before 8 minutes have passed, the switching device delivers to the comparison device 36 a signal which increases the spindle speed and activates lamp 41 to indicate this condition. At the same time, the switching device 34 resets the time transducer 31 to zero via control conductor 35 so that surveying of the next cycle is initiated.

In order to prevent, after delivery of a signal by time transducer 31 to comparison device 36 during the same cycle, an opposite signal from being delivered by the switching device 34, the switch 42 is opened upon the running out of the time transducer 31 and is closed again upon its resetting to zero.

As can be seen, the time comparison may also be effected for the time needed for a plurality of cycles of the knotting device. In this case, it would only be necessary to regulate the time transducer accordingly and to provide in the switching device 34 a counter for preselection and determination of the desired number of cycles.

It is of course also possible if necessary to gradually regulate the control of the stepping motor 24 depending on the amount of the difference from the desired 'value to modify the control characteristic. This would only call for a modification of the time transducer and ofthe comparison device which is quite familiar to persons acquainted with the art.

I claim: 1. A method of controlling spinning machines having a number of spinning stations, the spindles of which are rotated by means of a spindle driving device, and at least-one automatic thread knotting device movable along the spinning stations, said method comprising the ing a number of spinning stations, the spindles of which are rotated by a means of a spindle driving device, and said apparatus comprising at least one sensor for cyclically surveying the individual spinning stations in said spinning machine, means for determining the number of thread breakages in each cyclic survey, comparison means for comparing said number of thread breakages with at least one predetermined limit value, and a signal device controlled by the said means for adjusting said spindle driving device for reducing the spindle speed upon increase of the number of thread breakages and for increasing the spindle upon reduction of the number of thread breakages.

3. The apparatus according to claim 2, including an automatic thread knotting device, adapted to cyclically move past a number of spinning stations together with said sensor and a surveying station constituting said comparison means for comparing the time taken by said thread knotting device for one cycle with a predetermined time.

4. The apparatus according to claim 3, in which said surveying station comprises a time switching installation including a switching device for activating a time measuring process of predeterminable duration upon the start of each cycle of said thread knotting device and for stopping the time measuring process after termination of the cycle, and a time transducer controlled by said switching device connected together with said switching device by way of said comparison means, to control said spindle driving device so as to switch to a higher spindle speed if the time needed by said thread knotting device is shorter than the predetermined time and to a lower spindle speed if the time needed by said knotting device is longer than the predetermined time.

5. The apparatus according to claim 2, including a counting device, said sensor being connected with said counting device for adding thread breakages registered by said sensor, means for delivering from said counting device control signals, depending on the number of thread breakages during a determined period of time and a stationary interrogator connected to said comparison means and adapted to receive said control signals.

6. Apparatus according to claim 2, in which said sensor is moved cyclically along a plurality of spinning stations.

7. The apparatus according to claim 6, including a member for delivering control signals to said spindle driving device said comparison means being connected for the continuous control of said member.

8. The apparatus according to claim 2, including a counting device, said sensor being connected with said counting device for adding thread breakages registered by said sensor, means for delivering from said counting device control signals, depending on the number of thread breakages during a predetermined period of time, and a stationary interrogator connected to said comparison means and adapted to receive said control signals, said counting device being fixed to said sensor and movable along said spinning stations together with said sensor.

9. The apparatus according to claim 8, in which said counting device comprises a storage device for registering the number of thread breakages during a predetermined surveying cycle and in which said stationary interrogator is adopted to receive the contents of said storage device after a cycle has been terminated.

10. The apparatus according to claim 9, in which said storage device comprises a number of iron cores the magnetic polarity of which is determined under the control of said counting device to represent the number of thread breakages during said predetermined time.

11. The apparatus according to claim 10, in which reed relays are mounted on said interrogator and are allocated to said iron cores to be influenced thereby during the passage of said cores past said interrogator.

12. The apparatus according to claim 11, in which said iron cores are arranged beside each other to be magnetized by the sensor signals in the binary code to a stepping motor for controlling said potentiometer. 

1. A method of controlling spinning machines having a number of spinning stations, the spindles of which are rotated by means of a spindle driving device, and at least one automatic thread knotting device movable along the spinning stations, said method comprising the steps of cyclically surveying the number of the thread breakages in the individual spinning stations, continuously comparing the number of thread breakages surveyed in each cycle with a predeterminable limit value, and depending on whether the said number exceeds or falls short of the limit value, reducing or increasing the speed of the spindle driving device.
 2. Apparatus for controlling a spinning machine having a number of spinning stations, the spindles of which are rotated by a means of a spindle driving device, and said apparatus comprising at least one sensor for cyclically surveying the individual spinning stations in said spinning machine, means for determining the number of thread breakages in each cyclic survey, comparison means for comparing said number of thread breakages with at least one predetermined limit value, and a signal device controlled by the said means for adjusting said spindle driving device for reducing the spindle speed upon increase of the number of thread breakages and for increasing the spindle upon reduction of the number of thread breakages.
 3. The apparatus according to claim 2, including an automatic thread knotting device, adapted to cyclically move past a number of spiNning stations together with said sensor and a surveying station constituting said comparison means for comparing the time taken by said thread knotting device for one cycle with a predetermined time.
 4. The apparatus according to claim 3, in which said surveying station comprises a time switching installation including a switching device for activating a time measuring process of predeterminable duration upon the start of each cycle of said thread knotting device and for stopping the time measuring process after termination of the cycle, and a time transducer controlled by said switching device connected together with said switching device by way of said comparison means, to control said spindle driving device so as to switch to a higher spindle speed if the time needed by said thread knotting device is shorter than the predetermined time and to a lower spindle speed if the time needed by said knotting device is longer than the predetermined time.
 5. The apparatus according to claim 2, including a counting device, said sensor being connected with said counting device for adding thread breakages registered by said sensor, means for delivering from said counting device control signals, depending on the number of thread breakages during a determined period of time and a stationary interrogator connected to said comparison means and adapted to receive said control signals.
 6. Apparatus according to claim 2, in which said sensor is moved cyclically along a plurality of spinning stations.
 7. The apparatus according to claim 6, including a member for delivering control signals to said spindle driving device said comparison means being connected for the continuous control of said member.
 8. The apparatus according to claim 2, including a counting device, said sensor being connected with said counting device for adding thread breakages registered by said sensor, means for delivering from said counting device control signals, depending on the number of thread breakages during a predetermined period of time, and a stationary interrogator connected to said comparison means and adapted to receive said control signals, said counting device being fixed to said sensor and movable along said spinning stations together with said sensor.
 9. The apparatus according to claim 8, in which said counting device comprises a storage device for registering the number of thread breakages during a predetermined surveying cycle and in which said stationary interrogator is adopted to receive the contents of said storage device after a cycle has been terminated.
 10. The apparatus according to claim 9, in which said storage device comprises a number of iron cores the magnetic polarity of which is determined under the control of said counting device to represent the number of thread breakages during said predetermined time.
 11. The apparatus according to claim 10, in which reed relays are mounted on said interrogator and are allocated to said iron cores to be influenced thereby during the passage of said cores past said interrogator.
 12. The apparatus according to claim 11, in which said iron cores are arranged beside each other to be magnetized by the sensor signals in the binary code to represent the number of thread breakages.
 13. The apparatus according to claim 2, including a potentiometer controlled by said comparison device and connected to said spindle driving device to regulate the spindle speed.
 14. The apparatus according to claim 13, including a stepping motor for controlling said potentiometer. 